Field of the Invention
The inventions disclosed and taught herein relate generally to bypass cooling assemblies, and more specifically are related to reverse bypass cooling assemblies adapted to carry heat away from bearing assemblies during bearing operation.
Description of the Related Art
Segmented bearing assemblies are known and includes a plurality of arcuate pads, each tilting through a small angle so as to create a thin wedge shape opening between a shaft and an inner surface of the pad. The opening allows developing a film of oil which supports the load. However, because the film of oil interface is sheared as the oil is dragged through the bearing interface, the oil temperature rises. If the oil temperature rises sufficiently, its viscosity falls, and if the temperature rises substantially, its viscosity falls to a point where there is a direct rubbing of the metal shaft on the metal bearing surfaces, resulting in greater friction which may increase the bearing temperature to destructive level.
U.S. Pat. No. 5,738,447 to Nicholas, which belongs to the same assignee as the present application and is fully incorporated herein by reference, discloses a pad bearing assembly and more specifically, to a pad bearing assembly which uses spray and blocker bars to more effectively and efficiently remove heated lubricating fluid and introduce cooler lubricating fluid into the bearing assembly. In addition, cool lubricating oil is injected directly onto the leading edge of the next pad and in the direction of the shaft rotation.
U.S. Pat. No. 6,485,182 to Nicholas, which belongs to the same assignee as the present application and is fully incorporated herein by reference, describes a non-flooded bearing assembly for supporting a rotating body and selected from tilting pad journal, tilting pad thrust and sleeve bearings, has a body made from AMPCOLOY™ and provided with babbitted bearing and outer surfaces. The bearing assembly has a combination of passages extending between the outer and bearing surfaces for delivering a pressurized liquid lubricant to the bearing surface. A plurality of heat transfer chambers are provided in the body separately from and at a distance from the bearing surface to convey the pressurized liquid lubricant carrying the heat generated by the bearing surface away from the assembly.
U.S. Pat. No. 5,738,447 and U.S. Pat. No. 6,485,182, cool inlet oil is introduced behind the tilting pads by the blocker bars and/or housing inlet holes. The cooling oil takes heat away from the pads and directs it into the drain thereby cooling the pads and allowing the bearing to operate at higher speeds and higher loads. This is called bypass cooling. In U.S. Pat. No. 5,738,447 and U.S. Pat. No. 6,485,182, the bypass cooling oil is sprayed in the direction of shaft rotation.
The inventions disclosed and taught herein are directed to a bypass cooling for tilting pad journal and titling pad thrust bearings wherein the cooling may be achieved by spraying the cool inlet oil downhill with gravity instead of always in the direction of the shaft rotation.